In the traditionally Walmart-weary city of Portland, the big box retailer woos concerned locals with plans to top a new store with the largest vegetated roof in the entire state of Oregon.

Say what you will about Walmart and its ongoing sustainability efforts, but it appears that the big box behemoth has done a bang-up job at winning over Portland-area naysayers and NIMBYists who have historically grabbed their torches and tried to chase the company out of town.

So how’d the world's largest retailer — 4,522 U.S. stores and counting — manage to do it?

They put a green roof on it.

Construction just commenced on a new 90,000-square-foot store in North Portland that will be home to not only the largest green roof in the green roof-happy city of Portland, but the largest green roof in the entire state of Oregon. When completed, the vegetated, carbon dioxide-absorbing roof atop the Hayden Meadows Walmart will measure 40,600 square feet. In terms of size, that's about 10,000 square feet larger than the city’s current largest green roof atop the affordable, LEED Gold-certified Ramona apartment complex on Quimby St. (!) in the Pearl District.

The mega-chain has been placing solar arrays atop its stores since 2008 and recently installed an array atop its 100th retail outpost in San Diego. Currently, the company boasts 62 megawatts of solar panels installed in the U.S. and that number is only expected to grow significantly (eat it IKEA). However, this will only be the retailer's second venture into topping its stores with rooftop meadows after testing the waters at a store in Chicago several years ago according to the Daily Journal of Commerce.

Maryhelen Kincaid, land use chairwoman of the East Columbia Neighborhood Association, was a touch surprised at the relative lack of fierce resistance against the development. “There’s not the huge outcry that you see in other neighborhoods. I believe that most (neighbors) have just said, ‘If you don’t like Walmart, then don’t shop there,’” Kincaid tells DJC Oregon.

Along with job creation and convenience, Kincaid singles out the massive green roof as one of the factors that won over the opposition. “We heard it’s state of the art and will provide some environmental benefits. Overall, we’re excited for the project to be happening.” There has, however, been some concern over the potential for traffic headaches as there is currently no public transportation servicing the development. No big shocker here as erecting giant, single-use stores with no connection to public transport is typically how the Arkansas-based retailer rolls.

The massive roof itself was designed in collaboration with the Audubon Society of Portland, the Urban Greenspaces Institute, and a handful of other organization and will feature three distinct levels, each measuring roughly 13,000 square feet. Each section of the roof will contain different levels of soil that will aid the Bureau of Environmental Services in determining which is best to reduce stormwater runoff during a three-year performance study. “If it is indeed this big, it would give us an opportunity to measure stormwater management performance on something we really don’t have,” Tom Lipan, a landscape architect with the BES, tells DJC Oregon. “We don’t have anything near it.”

Additionally, certain sections of the Walmart green roof will feature wildlife-attracting habitat features such as compost piles and water basins. “I’m personally hopeful at some point we might be able to provide some habitat for some wildlife, certainly for invertebrates. You might get some meaningful value above and beyond the stormwater,” explains Mike Houck, executive director of the Urban Greenspaces Institute.

As reported by EarthTechling, other sustainable features of the store will include the use of recycled construction materials, LED lighting in the parking areas, flooring made from recycled fly ash, and an HVAC system that recycles heat produced by the structure's freezer units.

And in other Walmart news, the company has decided to resurrect its holiday lay-away program.